Power sources are used to supply power for electric and electronic devices and apparatuses. And as electrical apparatuses are ubiquitous in today's world, myriad electrical power sources are used. Although these power sources are varied, many of them deliver power that may not be precisely constant in terms of either voltage or current. Even electrical power delivered over power lines may surge or attenuate depending on both source and load conditions. These power irregularities may damage or interfere with the proper operation of the electrical apparatuses that depend on power sources. These irregularities may result in not only poor performance and irregular device behavior.
One type of an electrical apparatus is a load-cell which may be a device that converts a force into an electrical signal. These load-cells may be used to weigh objects, for example. But the systems in which these load-cells reside may have an output that varies as a result of various factors, such as temperature, circuit specific influences, and power source variation, for example.
Electrical apparatuses and electronic devices may have an output signal that represents a physical measurement. The difference between the signal representation and the actual measurement may be called measurement error. Many different phenomena may cause measurement error. Noise mechanisms, for example, may cause measurement error. Thermal noise may cause the resistors of a load-sensor, for example, to cause measurement error. Cross-talk from nearby wires and traces may couple into the measurement path and cause measurement error. Power supply rejection may be the term used to denote a circuit's ability to reject noise from the circuit's power supply. Power supply variation may be one source of power supply noise. The power supply noise that is not rejected by an apparatus or device may contribute to measurement error.